Barr body

American  

[bahr] / bɑr /

noun

1. a condensed, inactivated X chromosome present in most female mammals in the nuclei of all cells except the germ cells: used, as in sports competitions, to verify that an individual is genetically female.

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Etymology

Origin of Barr body

First recorded in 1960–65; named after Murray L. Barr (1908–88), Canadian physician

Example Sentences

In female cells, most of the genes in one of the X chromosomes are inactivated, forming a condensed region in the nucleus known as a Barr body.

From Textbooks • Jan. 1, 2018

Early in development, when female mammalian embryos consist of just a few thousand cells, one X chromosome in each cell inactivates by condensing into a structure called a Barr body.

From Textbooks • Apr. 25, 2013